A typical grocery shopping cart as used in grocery stores comprises a base frame, supporting wheels and a bottom rack or tray for carrying large bulky purchases such as bags of dog food and the like, an upper basket extending over top of the bottom tray, and a handle bar for pushing the cart about the store.
When the top basket is relatively full, items placed upon the bottom tray are, many times, hidden from view and may go unnoticed by the check out cashier.
Thus an effective means is needed to detect items, placed on the bottom tray of a grocery shopping cart, that may be hidden from view of the check out cashier.